从字符串中删除带哈希符号的链接

Question

我有一个包含HTML内容的数据库,它有一些带链接的文本.有些文本的URL中有哈希符号,有些则没有.

我需要删除带有哈希符号的链接,保留那些没有哈希符号的链接.

例:

输入:

<a href="http://example.com/books/1">The Lord of the Rings</a>
<ul>
    <li><a   href="http://example.com/books/1#c1" >Chapter 1</a></li>
    <li><a name="name before href" href="http://example.com/books/1#c2">Chapter 2</a></li>
    <li><a href="http://example.com/books/1#c3" name="name after href">Chapter 3</a></li>
    <li><a href="http://example.com/books/1#cN" target="_blank">Chapter N</a></li>
</ul>
<br><br>
<a href="http://example.com/books/1">Harry Potter</a>
<ul>
    <li><a href="http://example.com/books/2#c1" target="_self">Chapter 1</a></li>
    <li><a href="http://example.com/books/2#c2" name="some have name" title="some others have title" >Chapter 2</a></li>
    <li><a href="http://example.com/books/2#c3">Chapter 3</a></li>
    <li><a href="http://example.com/books/2#cN"  >Chapter N</a></li>
</ul>

期望的输出:

<a href="http://example.com/books/1">The Lord of the Rings</a>
<ul>
    <li>Chapter 1</li>
    <li>Chapter 2</li>
    <li>Chapter 3</li>
    <li>Chapter N</li>
</ul>
<br><br>
<a href="http://example.com/books/2">Harry Potter</a>
<ul>
    <li>Chapter 1</li>
    <li>Chapter 2</li>
    <li>Chapter 3</li>
    <li>Chapter N</li>
</ul>

我正在尝试使用此代码,但它删除了所有链接,我想保留那些没有哈希符号的链接.

$content = preg_replace('#<a.*?>([^>]*)</a>#i', '$1', $content);

所以,目前我得到这个:

The Lord of the Rings
<ul>
    <li>Chapter 1</li>
    <li>Chapter 2</li>
    <li>Chapter 3</li>
    <li>Chapter N</li>
</ul>
<br><br>
Harry Potter
<ul>
    <li>Chapter 1</li>
    <li>Chapter 2</li>
    <li>Chapter 3</li>
    <li>Chapter N</li>
</ul>

更多细节:

• 我正在使用PHP.
• 唯一的参考我必须知道删除的链接是de#symbol.
• 有些链接有新的一行.

例:

<a href="http://example.com">
    new line</a>
or
<a href="http://example.com">new
    line</a>

Answer 1

您应该避免使用正则表达式,而应该使用DOMDocument和DOMXPath.

<?php
$dom = new DOMDocument();

$dom->loadHtml('
<a href="http://example.com/books/1">The Lord of the Rings</a>
<ul>
    <li><a   href="http://example.com/books/1#c1" >Chapter 1</a></li>
    <li><a name="name before href" href="http://example.com/books/1#c2">Chapter 2</a></li>
    <li><a href="http://example.com/books/1#c3" name="name after href">Chapter 3</a></li>
    <li><a href="http://example.com/books/1#cN" target="_blank">Chapter N</a></li>
</ul>
<br><br>
<a href="http://example.com/books/1">Harry Potter</a>
<ul>
    <li><a href="http://example.com/books/2#c1" target="_self">Chapter 1</a></li>
    <li><a href="http://example.com/books/2#c2" name="some have name" title="some others have title" >Chapter 2</a></li>
    <li><a href="http://example.com/books/2#c3">Chapter 3</a></li>
    <li><a href="http://example.com/books/2#cN"  >Chapter N</a></li>
</ul>
', LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);

$xpath = new DOMXPath($dom);

foreach ($xpath->query("//a") as $link) {
    $href = $link->getAttribute('href');

    // link has a # in it, so replace with the links title
    if (strpos($href, '#') !== false) {
        $link->parentNode->nodeValue = $link->nodeValue;
    }
}

echo $dom->saveHTML();

https://3v4l.org/8FQYb

结果:

<a href="http://example.com/books/1">The Lord of the Rings<ul>
    <li>Chapter 1</li>
    <li>Chapter 2</li>
    <li>Chapter 3</li>
    <li>Chapter N</li>
</ul><br><br><a href="http://example.com/books/1">Harry Potter</a><ul>
    <li>Chapter 1</li>
    <li>Chapter 2</li>
    <li>Chapter 3</li>
    <li>Chapter N</li>
</ul></a>